Shale gas, coal seam gas… what’s the difference?

By Tsuey Cham

A few weeks ago we took a look at coal seam gas (CSG) and the hydraulic fracturing (‘fraccing’) process used in its extraction. You may have also heard of shale gas, another type of natural gas found deep underground.

So what exactly makes them different?

In terms of their gas content they’re really quite similar, with both made up predominantly of methane – the type of gas used in homes for cooking and heating.

However, when it comes to extraction and production CSG and shale gas can be quite different. For example, CSG can be found up to about 1000 meters underground, whereas shale gas is found much deeper, usually 1500 to 4000 meters below the surface.

In Australia, hydraulic fracturing – a technique that increases the rate of gas flow for extraction – is used in CSG production 20-40% of the time, whereas in shale gas production it’s used every time.

Another interesting difference is that the process used to extract CSG produces more water than it uses – so there are large quantities of water produced as a by-product. Conversely, for shale gas, the extraction process uses more water than it produces.

Watch our latest short animation to find out more about shale gas, how it’s extracted and some of the potential environmental challenges involved in its production:

If you missed the animation on CSG extraction, watch it here.

You can also find out more from our fact sheets on CSG, shale gas and hydraulic fracturing in coal seams.


Five facts you didn’t know about hydraulic fracturing (fraccing)

If you type the word ‘fraccing’ into Google you will immediately see how complex a topic it is.

The process of hydraulic fracturing involves pumping fluid underground at high pressure to fracture rock and release trapped gas.

We thought we’d shed some light on the technique with five top facts and a new video which explains what coal seam gas is, how it is extracted and what some of the challenges are.

Top 5 facts about hydraulic fracturing:

Hydraulic fracturing infographic

Five facts about hydraulic fracturing

  1. Hydraulic fracturing typically takes place a few hundred metres below ground for coal seam gas and up to 4000 metres for shale gas
  2. The technique has been around since the 1940s
  3. In Australia it is used in 100% of shale gas developments and 20-40% of coal seam gas wells
  4. Typically 5 to 30 megalitres of water is used when fraccing a shale gaswell (US figures), and 0.5 to 3 megalitresfor coal seam gas wells
  5. The fluid used in fraccing is approximately 99% water & sand, and 1% chemical additives.

To get a better understanding of coal seam gas and hydraulic fracturing visit our website www.csiro.au/unconventionalgas


Coal seam gas emissions lower than US: first Australian study

The methane-detecting four-wheel-drive, measuring emissions around Queensland and NSW coal seam gas wells. Tests were also done upwind of each site to avoid cows or other methane sources skewing the results. CSIRO, CC BY-SA

The methane-detecting four-wheel-drive, measuring emissions around Queensland and NSW coal seam gas wells. Tests were also done upwind of each site to avoid cows or other methane sources skewing the results.

By Damian Barrett and Stuart Day

One of the most common questions Australians ask about coal seam gas is whether the gas wells leak – and if so, how much?

In the first Australian study of its kind, new CSIRO research now gives an indication of how much those “fugitive emissions” might be, and how we can start to reduce them.

Commissioned by the federal Department of the Environment and now published on its website, the pilot study measured emissions around 43 coal seam gas production wells – six in New South Wales and 37 in Queensland – out of the more than 5000 wells currently operating around Australia. The results reveal that:

  • nearly all of the 43 wells tested showed some fugitive emissions;
  • the emissions rates were very low (in most cases less than 3 grams of methane per minute – equivalent to methane emissions from around 30 cows);
  • in many cases, those emissions could be reduced or even stopped entirely; and
  • the average measured levels from the Australian wells were 20 times lower than reported in a study of fugitive emissions from US unconventional gas sites, published last year in the leading international journal Proceedings of the National Academy of Sciences

In Australia, fugitive emissions from coal mining, oil and gas production account for about 8% of Australia’s greenhouse gas emissions.

From the latest report on Australia’s greenhouse gas emissions, published by the federal Department of the Environment in April this year. Quarterly Update of Australia’s National Greenhouse Gas Inventory: December 2013. Click to enlarge

From the latest report on Australia’s greenhouse gas emissions, published by the federal Department of the Environment in April this year. Click to enlarge

Although those fugitive emissions are estimated and reported under the National Greenhouse and Energy Reporting Act, there has often been a high degree of uncertainty associated with these estimates in Australia – particularly from coal seam gas production.

That’s why this new research is important, as it offers a first indication of fugitive emissions from coal seam gas under Australian conditions.

Pressure regulator

The report found a particular type of pressure regulator installed at many wells was a common source of methane leakage.

The report’s results

Our new report, Field Measurements of Fugitive Emissions from Equipment and Well Casings in Australian Coal Seam Gas Production Facilities, shows that of the 43 wells studied, three had no detectable leaks.

Of the rest, 37 wells emitted less than 3 grams of methane per minute, and 19 of those showed very low emission of less than 0.5 grams of methane per minute.

However, at a few wells (6 of the 43) much higher emissions rates were detected, with one well registering emissions 15 times higher than the study average. That was found to be mainly due to methane discharging from a vent on a water line.

On closer scrutiny, some of the leaks were due to faulty seals on equipment and pumps, which could be easily fixed, while other emissions were associated with exhaust from gas-fuelled engines used to power water pumps that are not regarded as “fugitive” emissions.

We tested for emissions using a four-wheel-drive fitted with a methane analyser. The car made several passes downwind from the well to measure total emissions emanating from the site.

To ensure that other potential methane sources, such as cattle, were not inadvertently included, similar measurements were made upwind of each test site. We also took a series of measurements at each well to locate sources and measure emission rates.

The methane-detecting 4WD and its equipment

The methane-detecting 4WD and its equipment

Why worry about fugitive emissions?

Fugitive emissions occur when methane escapes from production facilities, wells, pipes, compressors and other equipment associated with coal mining or natural gas extraction. Other human induced methane emissions occur through grazing of domestic stock, agricultural production and from landfills.

In nature, methane is released from geological sources and biological processes occurring in wetlands, swamps, rivers and dams. About 15% of human emissions of methane are derived from fossil fuels.

While burning gas for energy has lower greenhouse gas emissions compared to other fossil fuels like coal, methane has a global warming impact at least 25 times that of carbon dioxide (when measured over a 100 year period).

Even small losses of methane during gas production, processing and distribution have the potential to reduce the relative greenhouse benefit of natural gas as a fuel for electricity production.

Fugitive emissions can be costly for the coal seam gas industry because escaping gas represents a loss of a valuable commodity.

What’s next for CSG emissions research?

These new findings from 43 wells are a good start, but they are clearly only the beginning, given that represents fewer than 1% of Australia’s coal seam gas wells. More measurements are required to representatively sample the remaining 99% of wells before we can make definitive statements about methane fugitive emissions in Australia.

CSIRO scientists, through the Gas Industry Social & Environmental Research Alliance (GISERA), are undertaking further research into methane emissions in Australia including understanding the natural or background emissions of methane that come from seeps in the ground in Queensland’s Surat Basin.

This research aims to identify background sources of methane and determine the best detection and measurement methods.

Results from measuring naturally occurring methane seepage, as well as the results of this new report and others, will add to the bigger picture of assessing the coal seam gas industry’s whole of life cycle greenhouse gas emission footprint. Most importantly, we hope they will provide more answers to Australians’ question about coal seam gas.

This article was originally published on The Conversation.
Read the original article


The challenge of sorting fact from fiction on coal seam gas

Fracking site wellhead

Credit: Wikipedia Commons

By Alex Wonhas, CSIRO

Can you match the following three statements with the answers just below?

  1. Coal seam gas is bad for the environment and we should all protest against its use.
  2. Genetically modified foods are a part of multinational plans to take over the world’s food supply.
  3. Wind farms are dangerous to human health and should be restricted.

a) Yes, everyone knows it is bad news.
b) Well, I used to think that, but now I wonder if I was being manipulated by interest groups playing upon my emotions.
c) I’m not really sure about that. I think there is more misinformation than information around.

I’m guessing if you passed these questions around at your family dinner table, you’d match different statements with different answers. This is largely because we tend to look for answers that suit our views – and often form our views based on what our “tribe” thinks.

But imagine a new technology came along – let’s call it Technology X – that could provide a source of energy for Australia, but which comes with social and environmental impacts. How would you form your opinion on it?

You might consider doing your own research, but be quickly overwhelmed by the amount of information for and against, and not know quite what to believe. At that point you might look for the opinion of somebody you trusted, or make a decision based on your intuition. In this article I encourage you to form your own opinion based on your own and independent assessment of the facts.

Our rational and emotional brains

Our intuition is a useful thing that has served us well for tens of thousands of years, keeping us from wandering out of our warm caves into the dark and dangers of the night – but it is something that has become less suited to the modern high-technology world.

We like to think we are rational beings. But when faced with uncertainty, we still have a tendency to make decisions based on emotions, before looking for information to support our decision; even sticking with that decision when data proves it is wrong.

What if we were able to put that aside and make decisions on contentious issues, such as coal seam gas, based on our own individual assessment of the data?

What is conventional versus non-conventional gas?. The Grattan Institute, Getting Gas Right, June 2013.

As with any issue, there are interest groups on all sides that would have you believe that they are the only people providing a true interpretation of the data.

Yet despite differences on interpretations, there are some common things we should be able to agree on about unconventional forms of gas, including coal seam gas and the process of hydraulic fracturing (often nicknamed fracking or fraccing). Some of these coal seam gas facts include that:

  • There are clear benefits and there are clear risks.
  • There are many overstated benefits and there are many over-stated risks.
  • There are impacts on the economy, environment and communities, and it is not really possible to talk about one without including the others.
  • Despite all the things we know, there are still some unknowns.

Putting bad science to the test

A healthy approach to any contentious issue is to treat all information as possibly coming from a self-interested point of view, until you can confirm it or not.

There are some great resources for testing the claims of dubious alternative medicines, such as Quack Watch and of the claims of major pharmaceutical companies such as Bad Science. But where do you go to test the claims being made about unconventional gas?

I’d start by saying look at the calibre of the data, rather than the source. What studies support the statements being made? Who conducted them? Where were they published? Has any independent source agreed with the claims, or disputed them? When figures are given, do they give all the information needed?

As well as giving this scrutiny to statements you’re a bit uncertain of, it’s also useful to apply it to those that appeal to you.

Deciding whether coal seam gas is good or bad is wholly dependent on the individual’s definition of the words “good” or “bad”.

It is in the interests of the industry to make you believe that coal seam gas is good for Australia, while the opposite is true for other groups. The role of scientists, and organisations such as the CSIRO, is to act as an honest broker and try to bring some clarity to the debate.

We know that coal seam gas can be used as a source of energy and that Australia has vast reserves. But we also know that its development can have environmental and socio-economic impacts on our rural communities.

CSIRO’s aim is to inform the community, government and industry about the risks and opportunities that stem from developing Australia’s unconventional gas resources.

It is a complex issue, and a divisive one. There are things we know and there are things we don’t.

So what would you like to know? Please leave your questions and comments below, and let’s start the discussion.

Alex Wonhas will be available between 3-4pm AEST today (Tuesday 22nd July) to answer your questions about coal seam gas, fracking, or other issues related to unconventional gas.

Alex Wonhas oversees a team that receives funding from the Gas Industry Social and Environmental Research Alliance (GISERA), which is a collaborative vehicle co-funded by CSIRO, Australia Pacific LNG Pty Ltd and QGC to undertake research that addresses the social and environmental impacts of Australia’s natural gas industry. The partners in GISERA have invested more than A$14 million over five years to research the environmental, social and economic impacts of the natural gas industry. GISERA projects are overseen by an independent and publicly transparent Research Advisory Committee and made publicly available after undergoing CSIRO’s peer-review process.

This article was originally published on The Conversation.
Read the original article.


How coal seam gas is changing the face of rural Queensland

The Ruby Jo coal seam gas central processing plant, near Chinchilla in Queensland’s Surat Basin, October 2013. Image: AAP/Dave Hunt

The Ruby Jo coal seam gas central processing plant, near Chinchilla in Queensland’s Surat Basin, October 2013. Image: AAP/Dave Hunt

By Tom Measham, Senior Research Scientist and David Fleming, Research Economist

Why would young Australians buck international trends and move to the country? According to our research, a growing youth population has been observed in coal seam gas (CSG) development areas within the Surat and Bowen Basin regions of Queensland in recent years.

In contrast to other rural areas of Queensland, where the youth population is not growing, those two regions taking in areas such as Chinchilla and Moranbah have seen their youth population grow.

For example, in Chinchilla there were 1,112 young people aged 15 to 29 years old in 2006; just five years later, the number of young people had increased by about 46% to 1618. Out of that total, the male youth population in Chinchilla jumped 53% (to 978 young men), while the female youth population rose by 36% (to 640 young women).

This noteworthy increase in rural youth – for both men and women – is also seen in the broader regions of the Surat and Bowen basins, where CSG development is happening.

Regions in Bowen and Surat basins, Queensland.

Figure 1. Regions in Bowen and Surat basins, Queensland.

Over the same period, family incomes have grown and overall employment has increased.

However, in studying the impacts of unconventional gas development, the one negative trend we found was that agricultural employment had decreased more than the rest of rural Queensland during the expansion of the coal seam gas industry.

A re-injection of youth

Declining populations in rural regions is a worldwide phenomenon. That’s because young people are usually the first to leave, seeking employment, training and education opportunities in cities.

After gaining new skills and experience, 20-somethings tend to stay in urban areas rather than return to their rural homelands. And women are more likely to leave rural areas than men.

The combined impact of these trends is a reduction in the skills base of rural areas and a skewed population, with more older people and far more men.

In figures 2 and 3, we track the age group which was 15-19 in 2001 though time up until 2011. In the control group, which is made up of other comparable rural Queensland regions (dark grey line), the youth population is at its lowest when this group hits their early 20s. By contrast, for communities in coal seam gas areas (blue line) the youth population is increasing throughout their 20s as more people stay in the region and others come to the region as CSG development takes off.

Changes in female youth over time (ABS 2013). The blue line is the average for towns and communities where CSG development occurs. The dark grey line is the average for regions without CSG development (control). The green line represents Chinchilla.

Figure 2. Changes in female youth over time (ABS 2013). The blue line is the average for towns and communities where CSG development occurs. The dark grey line is the average for regions without CSG development (control). The green line represents Chinchilla.

Changes in male youth over time (ABS 2013). The blue line is the average for towns and communities where CSG development occurs. The dark grey line is the average for regions without CSG development (control). The green line represents Chinchilla.

Figure 3. Changes in male youth over time (ABS 2013). The blue line is the average for towns and communities where CSG development occurs. The dark grey line is the average for regions without CSG development (control). The green line represents Chinchilla.

We’ve singled out the case of Chinchilla (green line) as an example of a turn-around in about 2006 from losing young people to gaining young people as the pace of CSG development speeds up.

Because these increases occurred in male and female populations, the research suggests that the wider rural population are experiencing social and economic benefits from the CSG sector, rather than just a male workforce commuting from distant cities, as can happen with fly-in fly-out workforces in other contexts.

The fact that rural youth populations have grown in regions with CSG development is a significant finding and an important contributor to the health of rural communities.

In terms of the long-term future of rural communities,re-injection of youth may indeed be more important than the focus on jobs, which has traditionally been the main way that the industry has sought to demonstrate its benefit to rural communities.

More jobs in resources sector, but fewer in agriculture

Our research also found that jobs have increased in regions where CSG development has occurred.

During the ten years between 2001 and 2011, jobs in the resources sector across rural Queensland increased; notably this increase was about 31% more in CSG regions than in other rural Queensland regions. This figure is even higher when looking only at the Surat region, where it has grown by 45%.

For every new job in the resources sector there has been around two new jobs created in the related sectors of construction and professional services. By contrast, for each new job in the resources sector there has been a reduction of 1.7 jobs in agriculture.

These new jobs in CSG areas are not just restricted to males. Focusing on Chinchilla, total female employment increased 26% from 1204 in 2006 to 1516 in 2011. Over those five years, women left some agriculture and manufacturing jobs, but increased their employment in mining, construction and hospitality.

Family income and community welfare

Another important finding is that family income has increased more in regions where CSG development has occurred.

Family income increased by around 15% in the average region with CSG development when compared to other rural regions in Queensland. Family income is a useful measure of benefit because it provides an indicator of income that stays in the region, compared with other measures that may be affected by long-distance commuting workforces, who spend their income elsewhere.

However, while family income is up, this also has to be balanced against higher housing costs in some CSG regions such as Chinchilla.

We found that CSG regions had slightly more educated populations, but mostly among men. Poverty reduction was also observed in CSG regions, concentrated particularly in Chinchilla.

Finally, it is also important to consider the impacts of CSG development on other aspects of community well-being, such as noise and stress. These issues are currently being explored in related projects conducted by CSIRO.

This article was originally published at The Conversation. Read the original article.


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